A semiconductor device may include a semiconductor chip having a plurality of contact elements electrically coupled to a substrate in a flip chip configuration. The semiconductor chip may be underfilled with an electrically insulating underfill material. The underfill material should be void free to distribute any thermal expansion mismatch between the semiconductor chip and the substrate. A void free underfill material, however, is difficult to achieve because various propagation paths with different wetting dynamics and different capillary forces may exist in parallel. Air may be trapped when the propagation speed of the underfill material in these paths is strongly inhomogeneous. For example, the propagation of underfill material through contact elements may take longer than the wetting of the semiconductor chip sidewalls and the formation of a meniscus around the edges of the semiconductor chip. In this case, the sides of the semiconductor chip may be sealed off and an air bubble may be trapped before the underfill material has flowed through the contact elements. In addition, wire bond pads or other functional structures outside the perimeter of the semiconductor chip may be wetted by the underfill material, thus contaminating the wire bond pads or other functional structures.
For these and other reasons, there is a need for the present invention.